(1) Field of the Invention
The present invention relates to a mobile machine for distributing and shaping the ballast bed of a railroad track consisting of two rails fastened to ties, which comprises a machine frame, two undercarriages supporting the machine frame on the track for mobility thereon in an operating direction, and a ballast plow arrangement comprising a ballast planing plow including two vertically adjustable center plowshares arranged between the rails and a respective rail-bridging tunnel-shaped element associated with each rail and embracing the associated rail.
(2) Description of the Prior Art
U.S. Pat. No. 3,877,160, dated Apr. 15, 1975, discloses such a mobile ballast distributing and shaping machine. The ballast planing plow is mounted between the undercarriages and comprises an X-shaped, vertically adjustable center plow and two parallel rail-bridging tunnel-shaped elements. Three plowshares are arranged at the center of the center plow and are pivotal about a common vertical axis. Each tunnel-shaped element is connected with two transverse plowshares extending obliquely to the tunnel-shaped elements and these plowshares may be aligned with respective ones of the plowshares at the center of the center plow to constitute extensions thereof. A respective side plowshare is pivoted to an outer end of each transverse plowshare for pivoting about a vertical axis. At each side of the machine, a shoulder plow precedes the center plow for shaping the track shoulders. A ballast storage container with an hydraulically operable ballast discharge device is mounted on the machine frame immediately behind the center plow in the operating direction. An elevator conveyor band for conveying ballast is arranged between a broom arrangement at a rear end of the machine frame and a top of the ballast storage container. During operation of the machine, the two shoulder plows move the ballast in the track shoulders up in the direction of the center plow where the ballast is directed, depending on the positioning of the center plowshares, to each or one of the tie end regions. Any excess ballast is swept by the broom arrangement onto the conveyor band which conveys it into the storage container. While this ballast plow machine has been successfully used in track maintenance and rehabilitation work, the arrangement of a ballast storage container and a conveyor band feeding ballast thereto is not always suitable. In addition, the discharge of ballast from the storage container must be controlled by an operator, requiring additional personnel.
Austrian patent No. 378,795, published Feb. 15, 1985, discloses a ballast plow with a plow arrangement between the undercarriages of the machine frame and a ballast broom arranged at the rear end thereof. A transversely extending conveyor band precedes the ballast broom so that any excess ballast swept up by the broom is received by the conveyor band and is discharged on the ballast shoulder. This machine has also been successfully used but it often leaves cribs filled with insufficient amounts of ballast.